Compact Fluorescent Lamp Facts and Guidelines For Use



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Compact fluorescent lamps (CFLs) are marketed as an energy-saving replacement for incandescent bulbs, a commodity product that has been in use for more than 100 years. While incandescent lightbulbs remain a top choice among consumers, CFLs are more-cost effective and environmentally sustainable.

Facts about CFLs 

To help manage your CFL expectations and become an informed consumer, there is key information that you should know about the product. 

  • Because compact fluorescent lamps are not a commodity product, their initial purchase price is greater than an incandescent. Unlike the incandescent bulb, it uses more complex technology and is made up of several electrical components. However, the CFL saves consumers money over time because it uses less energy, lasts longer and requires less maintenance than an incandescent bulb if properly applied.
  • How you use CFLs will impact how long it lasts. In an environment with little airflow around the fixture, CFL life may be shortened because heat builds up. An example of a "hot" environment would be a recessed "can" or downlight. However, a CFL will thrive in a table lamp application where the fixture is exposed to airflow.
  • CFLs have a slight warm-up period of one to three minutes before reaching full brightness. This is not a flaw in the technology; the slow start-up allows the CFL to maintain constant light output while it is operating.

Guidelines on Using CFLs

There are also several guidelines to consider for maximal use of compact fluorescent lamps:

  • A CFL can appear dimmer than expected. This is normal among compact fluorescent lamps; however, this can be avoided by using the "Divide by 3” Rule. A CFL requires fewer watts than an incandescent to produce the same amount of light. Manufacturers use a 4:1 ratio for the wattage of an incandescent relative to a CFL. However, CFL performance can vary based on temperature and position, so a 3:1 ratio is instead recommended. For example, replace a 60 watt incandescent with a CFL that uses 20 watts, not 15 watts. You will still use only a fraction of the energy while avoiding the disappointment of a dim lamp.
  • Not all CFLs can be used with a dimmer. If the CFL is intended to be used for dimming, make sure the label on the box indicates that it can be dimmed. The same holds true if a "3-way" CFL bulb is needed to change the level of light output in a table lamp. The label should indicate that capability.
  • The color of light provided by CFLs has its pros and cons. CFLs are sold in different Correlated Color Temperatures (CCTs), and can be tailored for different decors; this is impossible with an incandescent lamp. However, color consistency can vary for the same type and manufacturer of a CFL. Two CFLs of the same type can look slightly different when seen side-by-side.
  • CFLs with the ENERGY STAR label are most recommended. The label indicates that the product meets strict energy efficiency guidelines set by the US Environmental Protection Agency and the US Department of Energy.
  • There is a recommended method of disposing CFLs. The lamps contain a very small amount of mercury, an essential element that allows them to be energy efficient. ENERGY STAR recommends that CFLs should not be disposed alongside ordinary household garbage; local recycling options are instead recommended. If a CFL broke by accident, certain guidelines are available via the ENERGY STAR website.

This article was updated on 12th February, 2020.


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